This invention relates, in general, to gas plumbing systems, and more particularly, to testing of the gas plumbing systems in vacuum systems.
Gas plumbing systems, gas manifold, or gas jungles have been used for a long time in a large number of industries. Gas jungles in the semiconductor industry are used extensively in a wide variety of equipment types such as chemical vapor deposition systems, etching systems, implanters, or the like. With increasing demands for greater productivity, fewer equipment failures, and less contamination, conventional maintenance procedures and methods are not adequate to meet these new stringent demands.
Conventional maintenance and trouble shooting of gas plumbing systems is a long, laborious, and costly procedure. Generally, for all gas related problems the equipment that is associated with the gas system has got to be taken out of production. The gas system is evacuated of all process gases and the entire system is checked for leaks. A determination as to exactly where and what has caused the gas related problem is then undertaken. Problems can be caused by a variety of items such as a contaminated gas source, a leak, a component failure, or the like.
Conventionally, if a component is suspected of being in need of repair or calibration it is removed from the gas jungle system to be tested, repaired and calibrated. Many times however, mistakes are made in diagnosing problems that result in removal of components in gas plumbing system that need not have been removed. The removal of components or parts of the plumbing system allows moisture and contaminated gases to be introduced into the system which contaminate inside surfaces of the gas plumbing system. This environmental contamination of the plumbing system can cause other problems when a process gas is reactive with the environmental contaminant. Thus, the removal of components results in lost production time, compromising the integrity of the system, and may result in causing a potential problem with reactions between process gas or gases and environmentally contaminated surfaces in the plumbing system.
Additionally, there is no method that allows for the in situ testing or calibration of a metering device. If the metering device is suspected of repair or calibration it is removed from the gas system and calibrated on a calibrated test fixture. Removal of the metering device results in all of the aforesaid problems.
Currently, there is not an easy method or apparatus to measure defectivity or particle levels that are associated with the process gases, gas manifold system, or gas jungle system. Generally, components of the gas system have to be taken apart in order to test for particle levels. When a defectively problem is suspected the equipment is removed from production and tested which typically involves breaking the vacuum integrity of the system.
Problems also exist with being able to sample, verify, and characterize gases that go through the gas system or jungle.
It should be evident that an apparatus and method that would allow in situ flow calibration, leak detection, particle checking and an ability to sample and verify gas quality would be very desirable.